This invention relates generally to ordnance fuzes and more particularly to an ordnance fuze which is safe and versatile wherein the arming energy is derived from the air environment.
Bomb fuzes may be categorized into two major groups: mechanical and electrical. Both groups employ out-of-line safety mechanisms powered by stored energy which is mechanical (e.g. springs) or pyrotechnic, i.e., electrically-initiated pyrotechnic devices.
Historically mechanical fuzes have provided comparatively good safety, but have suffered from a lack of tactical flexibility since no post-flight arming or functioning options are available to the pilot. Mechanical fuzes also present a severe logistical problem since a large number and variety of auxiliary components must be stocked, such as pyrotechnic delay elements, adapter boosters, arming wires, etc.
Electric fuzes in the past have demonstrated great versatility, including flight selection of arming and firing options. However, electric fuzing has safety shortcomings due to the general omission of environmentally-controlled arming.
Because of these fuzing safety shortcomings and lack of a cockpit-to-weapon communication link, weapons and fuzes have traditionally been shipped separately, thus creating extensive logistic, assembly and manpower expenditure problems. Much effort and many solutions have been proposed to these problems. For example, the stored energy used to power the out-of-line safety mechanisms has been replaced in some fuzes with means which sense environmental conditions, such as propellers or air vanes rotated by the airstream. Although this method has been quite acceptable, it is not entirely satisfactory since the weapon may achieve an armed condition far short of the target due to velocity variations and thereby, from a standpoint of maximum safety, much nearer to the delivery vehicle and personnel than is desired. Timing mechanisms have therefore been incorporated, but the disadvantage here is that the timers must be set when the bombs are loaded and cannot be changed prior to delivery if circumstances change.
The present invention embraces the advantages of existing fuze safing-and-arming (S & A) devices and yet possesses none of the aforedescribed disadvantages. The present S & A mechanism is sufficiently safe and rugged to be shipped and stored as an integral part of the weapon throughout the entire logistic cycle. Weapon explosive train safety is controlled by an air velocity environmental sensor and by a coded electric communication from the aircraft to the weapon. The environmental sensor controls the production of full or auxiliary electrical energy to operate electronic arming and functioning logic circuitry and the production and storage of the mechanical energy to effect arming of the fuze out-of-line explosive train.